Marsky,
I know for many flax seed and flaxseed oil are good options.
From the research I have done, flaxseed oil is high in omega 6's, so I no longer take it. Especially, since diets high in omega 6's promote inflammation, whereas diets high in omega 3's do the opposite. An ideal balance of omega 3 to omega 6 ratios is 1:1 of course.
I've been successfully using chia seeds (organic and whole, although they too can be ground) as its nutritional profile is quite good.
They are a good source of protein, and omega 3's, and a bunch of minerals as well. You may want to look it up and see if it fits with your needs.
I use a tablespoon of it in each of my protein shakes (made with almond milk).
As far as your pre-menopausal symptoms, you may want to look into Maca powder. It's all natural and has been around for a long time as an alternative to helping women cope with menopausal symptoms as it is adaptogenic. It also has the ability to help those with extreme fatigue, stress, decreased libido, and has helped men with impotence.
Of course, do your due diligence before trying any of these, and check with your doctor.